After an Asia tour lacking the fanfare of past trips, US President Barack Obama returned home to a gloomy set of problems that refuse to go away: Afghanistan, soaring unemployment, trundling health care reform.

A year ago it was all rock star welcomes for the man just elected America's first black president, but on Thursday a much grayer Obama slipped back into a rain-soaked White House largely under the radar of the world's media.

Accused by critics at home of scoring few concrete results in Asia, Obama's dipping popularity is unlikely to see any respite as he dives headlong into a host of divisive political decisions.

Obama must soon choose, after months of internal debate, whether or not to send tens of thousands more US troops into harms way in Afghanistan. The specter of a Vietnam-like quagmire, as ever, looms large.

His deliberations, punctuated by leak and counter-leak from government departments, have brought to the fore lingering doubts about who the US should be fighting in Afghanistan and to what end.

According to a recent Quinnipiac University poll, approval for Obama's Afghan policy has fallen sharply to 45 percent, and his presidential approval rating has slipped below 50 percent for the first time.

As part of a blitz of US television stations Obama recently told NBC the Afghan decision will be announced "over the next several weeks,"

"I'm confident that at the end of this process, I'm going to be able to present to the American people in very clear terms what exactly is at stake, what we intend to do, how we're going to succeed, how much it's going to cost, how long it's going to take," he said.

On the domestic front, Obama's plan to overhaul health care is also at a critical juncture. The Senate is soon expected to vote on its version of the controversial bill.

Support from within Obama's own Democratic party is far from assured, as shrieks about the bill's 849-billion-dollar price tag grow shriller from fiscal conservatives.

Still, Obama is unwilling to abandon his promise of having legislation in place by the end of the year, and with it a major political victory.

"I haven't given up on it. We're going to keep on pushing as hard as we can to make that happen," he told Fox News.

"It is a big complicated piece of business, and frankly, Congress is not accustomed, lately, to doing big complicated pieces of business like this."

Another key plank of Obama's election manifesto is also dragging: plans to shutter the Guantanamo Bay prison by January 2010.

Forced during his eight-day Asia tour to admit that the deadline would be missed, Obama is also under fire at home over his attorney general's decision to try five suspected September 11, 2001 attackers, including alleged mastermind Khalid Sheikh Mohammed, in New York in a civilian court as opposed to a military tribunal.

But perhaps Obama's biggest worry is still the economy.

Hours before departing for Asia, Obama sought to remind Americans that he still had his eye on the economic ball by announcing a White House summit on December 3 to address measures to ease the country's double digit unemployment.

"I spend every waking hour when I'm talking to my economic team about how, where are you going to put people back to work," Obama told Fox.